1. Field of the Invention
The invention concerns an improvement in the making up of ready to use doses of animal semen for artificial insemination, to be more precise a machine for making up such doses and the doses made up by the improved machine.
2. Description of the Prior Art
Artificial insemination using ready to use doses of semen to which a probe is fitted at the place of insemination has become standard practise, in agriculture in particular.
Doses made up in strips including sachets made from two films of flexible thermoplastics material fixed together by welds each delimiting a pocket with an approximately rectangular contour with one of the shortest sides interrupted are known in themselves and in these doses the weld defines, leading towards the exterior of the pocket from the interruption in the shorter side, a filler tube extended by a centering funnel widening in the direction away from the bottom of the rectangular pocket; the two films of thermoplastics material have holes outside the line of the weld for sprockets which feed the strip along the making up machine, and in particular into the station in which the pockets are filled; the two films are also welded together around these holes, locally increasing the stiffness of the strip and reducing the tendency of the strip to deform in this area during filling. As the sachets are still in a strip when filled, it is important to facilitate deformation of the pocket during this operation and, to this end, a long incision that subsequently delimits each sachet is made in the strip, transversely to the strip and between the successive pockets. The pockets are sequentially filled with semen, in conjunction with stepwise movement of the strip into the filler station, by means of a tubular needle connected to a tank of semen and introduced into the pockets in succession while the sachets are stationary in the filler station; to this end the needle is moved in longitudinal translation to insert its free end into the filler tube, remains stationary during filling, and is then moved in longitudinal translation in the opposite direction to withdraw it from the tube; in the next station the machine for making up the doses welds the two films of thermoplastics material together to join together the opposite walls of the centering funnel, forming a weld which closes and therefore seals the pocket.
The sachets are then separated by extending the incisions and then constitute doses ready for use.
When the doses are to be used, scissors, a stylet or any other cutting tool are used to make a transverse cut through the upper part of the centering funnel, for example a V-shape cut or even a straight cut, after which the free end of the tube of the probe is inserted into the filler tube of the dose via the funnel that has been opened up in this way.
The operations required are therefore simple and fast and the probe can be fitted to the dose in a very short time, which greatly reduces the risk of contamination of the semen by bacteria in the surrounding air, and insemination can begin immediately afterwards; insemination itself is also simple and fast and, the dose being held higher than the end of the probe, it is drained naturally by the combined action of atmospheric pressure, genital tractus of the animal and the intrinsic shape of the pocket, which is flat with no excess volume, and with no need for replacement of a volume of semen by the same volume of air as the semen flows out.
However, reservations have been expressed by some users, relating to the necessity of using a cutting tool at the place of insemination, since it is not possible to keep the tool sterile throughout the insemination of several animals, or even a large number of animals.
An object of the invention is to remedy this drawback and consequently to provide a ready to use dose of animal semen that avoids the use of a tool for opening it. As the problems to be solved to produce a dose of this kind are more difficult to solve than might be supposed at first sight, the invention is more particularly concerned with improvements to a machine for making ready to use doses of semen and the doses made up by means of that machine.